JPS58129051A - Ppe composition containing impact-resistant improver and melt viscosity lowering agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Polyphenylene ether resins are a well-known family of linear thermoplastic enchaining resins. A variety of these resins and many of their methods of preparation are described in US Pat. Nos. 3,306,874 and 3,306,875 to Hay, as well as US Pat.
No. 57358.

Polyphenylene ether resin is Chitsueku's U.S. Patent No. 3
It is miscible with other polymers as specified in No. 3,834,35 and can be mixed with thermoplastic elastomers conventionally used as auxiliary or modifying resins. Compositions of this type, many of which have been used to improve the impact resistance of articles molded from mixtures, are described not only in the Citzek patent, but also in Kutzper et al., U.S. Pat. No. 4101505 and No. 4
No. 172929 and others.

Many such compositions are naturally flammable.

"Flammable under normal conditions" means, as used herein, V-
On shall mean that the V-1 requirements are not passed. It is known that certain agents, such as aromatic phosphates, can be added to provide flame retardant (self-extinguishing) behavior and also to act as plasticizers for the composition. The compositions formed often have high heat deflection temperatures (the temperature at which the molded article begins to deform), good resistance to breaking or fracturing when subjected to impact,
and exhibits a good fire resistance combination. However, there have been some difficulties encountered during processing due to the high flammability of the resin in the molten state. High melt viscosity reduces the rate at which the resin can be molded in an injection molding machine and increases the power required to maintain a constant production rate from the extruder. Higher processing temperatures can be used, but this can result in depolymerization, oxidation or other resin degradation.

It has been proposed that the addition of low molecular weight hydrocarbon resins to certain polyphenylene ether resin blends may enhance processability by lowering molding temperature and melt viscosity. Compositions of this type are disclosed in Harf's U.S. Pat. No. 4,189.
No. 411 and British Patent No. 1,344,729.

When certain low molecular weight hydrocarbon resins are incorporated into unplasticized blends of polyphenylene ether resins and impact modifiers, the compositions formed have high heat deflection temperatures and good heat deflection temperatures as well as low melt viscosities that facilitate molding. It has now been discovered that this material has impact strength as a feature.

Preferably, the low molecular weight hydrocarbon resin is selected among coumaron-indene resins, cyclopentadiene-styrene resins, aromatic petroleum resins, cyclopentadiene-indene resins, phenol-coumarone-indene resins and alpha-methylstyrene resins. Commercially available forms are shown in the examples.

Polyphenylene oxide resins useful in compositions of this type are well known, as mentioned above. However, there are various preferred composition components. These are, in principle, common and have applications in which impact strength is particularly desired.

Preferred polyphenylenes and ethers have the formula (Q, Q'
, Q" and QIL/ are hydrogen, a hydrocarbon group, a halohydrocarbon group having at least two carbon atoms between the halogen atom and the phenol nucleus, a hydrocarbon oxy group and at least two carbon atoms between the halogen atom and the phenol nucleus each independently selected from the group consisting of halohydrocarbonoxy groups having atoms, q', q'' and QIIF can further be halogen. However, Q and Q' are preferably homopolymers and copolymers containing no tertiary carbon atoms, where n represents the total number of monomer residues and is an integer of at least 5o.

Particularly preferred is poly(2,6-dimethyl-1,4-phenylene ether).

These can be made according to the teachings of the patent specifications mentioned above.

Preferably, the polyphenylene ether resin is in a mixture with one or more polymeric impact modifiers. The impact modifier can be a sitastyrene homopolymer, or a styrene-containing elastomeric copolymer or homopolymer mixed with or modified with an elastomeric material such as natural or synthetic rubber.

By way of example, impact modifiers include natural or synthetic rubbers such as polybutadiene, polyisoprene, butyl rubber, l
<Homopolymers such as polystyrene, polychlorostyrene, poly(α-methylstyrene) or poly(bara-methylstyrene) modified with PDM rubber, natural rubber, polysulfide rubber, polyurethane rubber, etc.; elastic styrene copolymers such as styrene- Butadiene copolymers, styrene-acrylonitrile-butadiene terpolymers (ABS), various forms of block copolymers of styrene and dienes, such as A-B ^ -B-A
A-B-AB Block copolymers of the form A-B-A-B-A, random or radial teleblock copolymers of these same materials, including aliphatic unsaturations such as unsaturations of the "B" (diene) block Hydrogenated forms of linear, random and radial copolymers with reduced styrene, and any mixtures of the styrene homopolymers described above with any of the elastomeric styrenic co- and terpolymers described above.

The blend of polyphenylene ether resin and impact modifier can contain virtually any proportion of these materials, for example from 20:1 to 1:2 parts by weight.

Only small amounts of low molecular weight hydrocarbon resins are required to achieve the advantages of the present invention. At least about 0.1% by weight based on the total weight of the resin, typically about 1.0-25%
．． An amount of 0% by weight is typical. However, the amount of this component can vary widely within or outside this range according to individual requirements.

The molding compositions of the present invention are one of the auxiliary non-resin agents conventionally commonly present in polyphenylene ether resin molding compositions to improve certain other physical and chemical properties of molded articles. It is advantageous that it can contain more than one.

Such agents include antioxidants, reinforcing fibers (eg, glass fibers and graphite whiskers), mineral fibers, anti-wear components, dyes, pigments, and the like. Many such agents are described in Kutzper et al., US Pat. No. 4,172,929. These are present in small but effective amounts, usually from 1 to 50% by weight.

The composition is prepared by mixing the components in a conventional manner to form a premix, extruding the premix in a single or twin screw extruder, cooling, cutting the extrudate into moldable size pellets, It can be made by injection molding. Alternatively, a homogeneous melt of each component can be formed, cooled, cut or ground, and molded directly or first extruded and then molded.

The following examples illustrate the invention. These are presented only as preferred embodiments and are not intended to limit the scope of the invention. All parts are parts by weight.

Actual example: 80 parts of poly(2,6-dimethyl-1,4-phenylene ether) (PPO, General Electric Co., Ltd.)
Co., Ltd.), 10 parts polystyrene-polybutadiene-polystyrene (KG1651 from Shell Co. with a hydrogenated central block), 20 parts low molecular weight hydrocarbon resin as shown in the table below, 0.15 part zinc sulfide and 0.15 parts oxidation. The composition was made by mixing zinc. The mixture was extruded in a 285w twin screw Warner Prypler machine at 580°C and then 575°F (former temperature 270″F).
It was molded into a test bar at an injection temperature of . The results are shown in the table.

The patent specifications and/or publications mentioned above are incorporated herein by reference. Other modifications of the invention are clearly possible in view of the above description. For example, poly(2,6-cymethyl-1
．． poly(2,6-
Copolymers such as dimethyl-(2,3,6-drimethyl-1,4-phenylene ether) can be substituted.

The relative proportions of each component can be varied. It is therefore to be understood that variations in this example may be made that are within the intended scope of the invention as defined in the claims.

Claims (1)

Claims: 1. An unplasticized thermoplastic composition containing a blend of (ml polyphenylene ether resin and an impact modifier, and tb + an effective amount of a low molecular weight hydrocarbon resin. 2. .1% by weight of a low molecular weight hydrocarbon resin. 3. The composition of claim 11 JI containing about 1.0 to 25.0% by weight of a low molecular weight hydrocarbon resin. The composition according to item 1. 4. The low molecular weight hydrocarbon resin is coumaron-indene resin, cyclopentadiene-styrene resin, aromatic petroleum resin, cyclopentadiene-indene resin, phenol-coumarone-indene resin and α-methyl. 5. The composition of claim 1 selected from the group consisting of styrene resins and any mixtures thereof. 5. A polyphenylene ether resin having the formula (QSQ'
, Q" and Q"' represent hydrogen, a hydrocarbon group, a halohydrocarbon group having at least two carbon atoms between the halogen atom and the phenol group, a hydrocarbon oxy group and at least two carbon atoms between the halogen atom and the phenol group. each independently selected from the group consisting of halohydrocarbonoxy groups having carbon atoms, qlQ" and QIJ/ can be halogens, provided that Q and Q' do not contain tertiary carbon atoms. 6. The composition according to claim 1, wherein the polyphenylene ether resin is a poly( 7. The composition of claim 1, wherein the impact modifier is a block copolymer of styrene and butadiene. Composition. 8. The composition of claim 7, wherein the butadiene block is hydrogenated. 9. The polyphenylene ether and the impact modifier.
Claim 1 containing in a weight ratio of 0:1 to 1:2
Compositions as described in Section. 10. The composition of claim 1 containing non-resinous additives selected from the group consisting of: 10. antioxidants, dyes, pigments, mineral fillers and reinforcing fibers.